U.S. Air Force Airman 1st Class Timoteos Kim, (right) 633rd Logistics Readiness Squadron fuel distribution flight member, monitors Airman 1st Class Jerry Tondini, (left) 633rd Security Forces Squadron installation entry controller, with a Point Source Chemical Detector during a combined unit exercise at Langley Air Force Base, Va., Dec. 12, 2012. The chemical decontamination process included four zones—red, orange, yellow and blue—to ensure proper removal of simulated-contaminated mission orientated protective posture gear. (U.S. Air Force photo by Senior Airman Racheal E. Watson/Released)